Undercover
by Daisy60
Summary: Stuck on a case Beckett decides to go undercover with Castle. What is she up to? Read and find out. Reviews are appreciated.
1. Chapter 1

**Here's letter U. I'm having fun with Castle and Beckett once again, they're simply great to watch and write about. Have fun reading and stop by to leave your impressions. Feedback is important, thanks.**

**UNDERCOVER**

"I think we might need your Ferrari after all Castle" Beckett suggested raising her head from the file she had been reading for a while. That damn case was driving her crazy.

He looked at her and smiled brightening up at the idea that she was up to something _fun._

"So far Castle we have nothing but a bunch of dead ends. We might just as well have a good time while we go and see what was going on in that night club the day the girl disappeared."

"And we're using my Ferrari for...?" he hinted intrigued.

"We're going undercover Castle. Cheer up, I know you love _that_, don't you Rick?" she teased.

_And didn't he?_ _How couldn't he?_ The last time she had done her best to make him loose his mind by sweeping into a room to rescue him with nothing on but a stunning red dress so terribly short he had dreamed about her perfect long legs for a whole week... and so tight that every hot curve of her body had had him scream inside for... well, he had lost count about that. But red, really? The association between his car and that dress was permanently imprinted on his head and he honestly hoped she would choose a different dress this time or he might just as well...

"Castle focus!" she shouted making him jump from his chair "and stop fantasizing" she added trying to hide the huge smile that had formed on her face noticing the effect of the word _undercover _on her partner.

_Oh yes, she was definitely going to have a good time with her favourite ruggedly handsome writer..._

He blushed thinking she'd been reading his deepest thoughts. _Very well Detective Beckett -_ he said to himself giving her a wicked smile - _aren't we going to play this dance again? I'm all in._

"Ok then, tonight. Will come and pick you up at ten. Think about something fancy to wear, we need your charming Castle at his best to perform this." and she went back to her file.

"_Damn it Beckett!_" - he thought - this woman was _so_ going to kill him. "See you later."

**B&C**

"Richard darling, going out on a date?"

"No mother – he replied knowing she would not stop until she was fully satisfied with her share of teasing – going undercover."

"Oh I see, with your fav NYPD detective I suppose..."

"Obviously not with Esposito" he snapped as he gave himself a last look in the mirror.

"Guess he doesn't appreciate that _very expensive_ cologne you've put on" she mocked.

_But she will_ – he thought – knowing Beckett had told him so on a previous occasion.

"Kate you look amazing" – said Martha letting her into the apartment.

"Thank you" she replied the colour rising on her cheeks.

Castle was speechless as he approached her in the living room.

_My God_ - he thought - _this is going to be real hard. _That black _very short_ dress which clings perfectly to her body like a glove... she is smoking hot!

"I'm ready" he told her showing proudly the key of his Ferrari.

"I'm driving" she stated matter-of-fact.

"You're what?" He gasped "This is a Ferrari Beckett...this car is designed to..."

"Right Castle" she said grabbing the key "Let's go... the night is still young"

Martha gave the two a wicked smile. "Have fun and please... don't come home too early!"

Beckett nodded while Castle looked so pissed off.

_Why on earth it was she driving all the time? Even his own car?_

He was really trying his best but man... he couldn't think straight and as she took her place at the driver's seat she pulled her very tight dress further up to adjust to a more comfortable position. Those long edible creamy legs would hunt him forever. Swallowing hard to keep his excitement under control he turned his eyes away from her. Beckett's lips turned upwards, she was enjoying every single moment of her night out with him, undercover or not. "One... two...three...four... bingo she said to herself as his eyes were back on her thighs.

She started to sway to the music the minute they stepped into the club joining in with the lively, chatting people on the dance floor.

_And_ _now... dammit... what is she doing? _She moved so dangerously close to him, brushing her incredible curves all over his body.

His only coherent reaction to her teasing was quite unexpected for Beckett. She found herself in his arms while she felt his right hand wandering on her thigh and slowly moving upwards.

"Castle!" she yelled "what the hell are you doing?" yet she relished the way he was touching her.

_How could possibly such a big, strong hand be so gentle and soft?_ She wondered trying to picture what kind of magic his hands could perform on her skin.

"Being my usual charming self?" "What do you pretend me to do anyway?" he replied seriously, as he shifted from her to hide his arousal. Her smell lingered around him and he just stood there and watched her move in sync with the music.

"Please Castle focus " she pleaded him already mourning the loss of his warm touch.

She leaned forward and whispered in his ear "Go and get some drinks while I try and sneak over there" she told him nodding in the direction of a man sitting on a sofa, a huge bodyguard before him and a couple of girls on both sides.

"Right, drinks. Will be back in a minute."

_And what did just happen now?_ He thought heading back to her holding two glasses in his hands.

The body guard was on his knees hands on his family jewels and she was pressing the other guy on the coffee table right in front of her. Better not to mess around with Katherine Beckett... the next thing he noticed was her badge flashing before the guy's face.

"Jesus Beckett – he let out – where were you hiding _that?"_

"Don't ask and pass me the handcuffs!"

"Ryan" she said holding her cell phone "you and Esposito will take care of the guy I'm sending you while I well... she lingered as the thought formed in her mind _will take care of Castle._

When all was back to normal Beckett and Castle resumed their position on the dance floor. She really didn't feel like wasting such a good opportunity to have some more fun with him. So she started once again to tease him like she had before. Only this time he grabbed her hips and pulled her close to his raging arousal. "Katherine Beckett you are so going to pay for behaving so boldly" his eyes lit with desire. A moan escaped her mouth as she felt his urge. _Quite impressive_ she thought. "Bad girls always get what they deserve?" She challenged him.

"You bet. Your place or mine?"

"Mine. No witnesses allowed to our party."

"Wow" he gulped.

Castle moaned and stirred on the bed. _Where was he? And why was it still dark? Ok, Beckett's place._ His head still felt slightly dizzy from the most mind blowing night of smoking sex with his favourite detective. She was everything he could think of to describe her. Sweet, tender, so damn feminine, wild and passionate and she had just matched his raging desire till they had collapsed in each other's arms. His body felt deliciously sore. A nice hot shower would just do then he'd make her a huge breakfast.

"Oh hell" he screamed as he was finally back to reality sensing the blindfold on his eyes and the cuffs on his his wrists. "Beckett?"

"morning Castle, ready for the best wake up call of your life?"

**A/N: I hope you liked this. If you did please review. I might turn some of these quick shots into more elaborate stories so let me know which are the ones you'd like me to develop. Till the next one...**


	2. Chapter 2

**I woke up to a sunny day this morning with a follow-up to Undercover lingering in my mind. I just want to have fun with my favourite couple and start the new year with a smile. I was asked to turn it into a multi-part story and here I am. Enjoy the reading.**

**A/N: I do not own any of these characters. **

**UNDERCOVER**

part 2

He couldn't see her but he could definitely smell her. How could he ever forget her scent? It had lingered around them all night. Not being able to see heightened his other senses to a peak he had never experienced before.

He moaned blissfully.

"Is _that_ all you can say?" She teased.

"Isn't it enough?" he replied a huge smile on his face.

Her lips curled up immediately.

"I guess you can do much better than that, Jameson."

Oh he loved that. She had switched to a little role play and he thought that he was going to enjoy every single minute of it.

"Anything to please you, Nikki."

It was her time to moan now. He was totally, undeniably, ruggedly handsome and so witty and clever with words she felt her mind drift away. Some of his cutest phrases flashed through her mind

_I'd be glad to let you spank me... never ever call me kitten... I can see you naked... separately! Why? Katherine Beckett I never... _

he could be dead serious and melt her with just one deep look of those illegal eyes of his then make her laugh out loud with his skilful way with words. Sometimes she had just managed to turn around not to show him how amused she was but he knew, oh he simply knew how to bring out her laughter, how to make her smile... and she adored him for that.

"So Rook..." - she resumed back to action – "you have been quite a bad boy, you're aware of that?"

"Yes." he whispered faking his concern.

"Now... what punishment do you think fit for behaving in such a way?"

"Remember, Detective..." - he said with a wicked smile on his face – "that my safe word is _apples_"

"Oh _that_ is not going to be enough, I assure you." in saying so she pulled her leg and started teasing his ankles with the tip of her shoe.

He sprung up from the bed pulling on the handcuffs and yelling at the pain he felt on his wrists.

"I wouldn't do that if I were you." she whispered leaning forward "just relax and get what you deserve, bad boy."

He nodded and lay still. _Come what may,_ he was at her mercy. He resigned to let her have her way with him.

She resumed her teasing with her foot slowly moving upwards on the inner side of his leg. His body immediately reacted to her touch and she smiled at the obvious effect her foot was having on a certain part of him. She stilled and enjoyed the sight of his manhood come to life for her.

Castle couldn't help but hold his breath as he heard her groan with pleasure beside him. She was obviously contemplating his growing arousal and biting her lower lip in that _oh so erotic_ way that was typically hers. The first time he had seen her do that leaning on him and whispering a challenging _You have no idea _something had clicked in his mind. He had rushed back home, switched on his laptop and in a frenzy of creativeness, had given birth to a character that was to render him even more famous than he already was.

He had found a new life in her. A new exciting inspiring life. And a woman who was so difficult to conquer that made everything about her so more intriguing and challenging. She was a nut to crack and her hidden fruit would be the most rewarding prize he would ever get.

"Take off the blindfold..." he begged urging to see her.

"Not yet. Now this is quite an interesting bit of evidence..." and she brushed his length letting him guess what she was was holding.

Castle gasped as he sensed hard leather touch his most intimate parts.

"Wow." he exclaimed as his toes curled with delight. "I want to see you do this." he pleaded.

There was a pause. Then he felt her deft fingers undo the knot behind his head and he blinked at the sudden brightness hitting his eyes. When he was able to focus again he almost passed out as the most stunning Cat Woman was standing right above him with a whip in her hand. Not much was left to his imagination and he drank in the sight of his partner at her very best in a tight leather black costume. His wild fantasies of her were nothing compared to the real creature before him. His eyes sparkled igniting her. She bent on him letting him feel the leather top covering her breasts.

"Never ever tell anyone what my favorite character is. Swear!" she commanded.

"I swear."

She kicked her incredibly high heeled black stilettos off and straddled him resuming her little whip play on his skin.

"Oh God Beckett I don't think I can handle..."

"I don't know who that is." she stated giving him a mischievous smile. - "Who am I?"

"You're Nikki."

"And... you think of me when you write about her..._don't you_?" she thought about the first time she has read the famous scene with the Tequila shots and heat had started spreading in her womb as if she had been actually taking them with him.

"So I _do_ inspire you Rook?"

"You know you do... I want to undress you."

"Oh no. You cannot. See? - and she nodded at his handcuffed wrists - "but you can watch..."

So she started an agonizingly slow strip on top of him, brushing him whenever she needed to make him stir almost desperately. When she was naked she placed her hands on both sides of his chest, leaned down on his lips and whispered softly into his mouth "Tell me what you want Rook."

"You... all I want is you Nikki. You're mine."

"I am." So she slid gently on him careful not to hurt him as she joined them. Her erotic foreplay had already put him on the edge and he looked at her in concern of what was about to happen.

"Kate I don't think I can last... I need to...please..."

"Me too." she confessed as she moved slowly around him, trying to make them both last as long as she could.

"Free me." he said sensing he was about to come apart.

She released his hands and he grabbed her rolling himself on top of her riding them over the edge leaving her astonished of his sudden unexpected move.

They lay lazily in each other's arms lightly running their hands on their still quivering skin. Suddenly she stopped and giggled.

"What's funny?" he inquired.

"Nothing... I was just recalling..."

"Care to share?"

"Oh you're definitely going to remember soon. Close your eyes and don't move Castle. Be back in a sec."

**A/N: so I'll leave you with a flea in your ear. What Is Beckett up to? Try and remember Castle fans. There's a reference to an ep. I will post Part 3 soon. **


	3. Chapter 3

**So here's part 3 of Undercover. I hope you liked part 2, I cannot check my stories stats as something went wrong in my FF account and I'm actually stuck, kind of blindfolded myself. The only contact I have with you is the automatic feedback on my email box. Has anything like this ever happened to you? I might add a final chapter to this, it's really fun to write about Castle and Beckett, they really are playful. So enjoy the reading.**

**A/N: I do not own any of this characters. **

**UNDERCOVER**

part 3

Beckett peeped through the door just in case.

"Are your eyes shut?" she asked.

"Yes."

"Good boy." she said approaching the bed placing what she held in her hands on the night stand.

"So what do good boys get at the end of the game?" he inquired teasing her.

"_You have no idea_..." she whispered in a husky voice leaning on his ear repeating the exact phrase that had ignited it all between them. "However bad your final punishment _Ricky boy_ you are not allowed to touch me. Is that clear?"

"Roger that!" she smiled at his absolute faith in her and she honestly feared for his sanity thinking of what she was about to do to him.

"Now no matter what... keep your eyes shut and your hands on the sheet."

He did his body reacting wildly to her words. How could she turn him on like that? No other woman had ever been so playful with him, daring to push the game a little bit further just for the fun of it. So preparing himself for the last torture she could possibly inflict on his already desperate throbbing body he kept his eyes firmly closed, grabbed the sheet and held his breath in anticipation.

"What can you smell Castle?"

"You... us..."

"You're right." she confirmed already addicted to the bitter-sweet scent of their making love that lingered in the room. "This sense would do no good for the time being... try and focus on … touch..."

"I love touch, I can go with that!" he mused.

She started to place hot wet kisses on the back of his ears, biting and sucking, leaving pulsing red marks wherever she lingered. When she reached his nipples he was already writhing in the most delicious agony he had ever experienced. He felt fire on her lips and stopped breathing when he sensed what part of his body she was going to attack.

"Your skin is so hot Rick... can you feel that?"

"Yes... you're setting me on fire and I'm willing to burn into your hell."

"Poetic till the very end..." She reached out on the night stand and took the bowl placing it next to her. Then she picked some of its precious content and put it in her mouth, a wide evil smile forming on her face then she dug her hand into the bowl.

He was lying below her waiting almost desperately for her to resume her touching him.

Suddenly, she placed her lips on him covering his length with her chilling cold lips retrieving her hand from the bowl and cupping his balls in a freezing grip. He yelled out her name clenching the sheet till his knuckles were white. She was amazed at his self control, he was actually keeping his word, playing the game through the finish line. She felt the heat spreading from her core as she covered him with the ice she had in her mouth. Before he could process what had just happened she quickly straddled him and took him into her warmth shivering at the clash of sensations in her body.

"Look at me." she said truly concerned about his well being because of the drastic change of temperature on the most delicate part of his body. "How does it feel?"

"A...MAZ...ING..." he panted melting his deep blue eyes into her green ones. "I swear..." – he went on - "I've never experienced anything like... _this_."

"Hold me Castle."

He released the sheet and placed his strong hands on her hips gently holding her as she rode them over the edge toward the final reward for their crazy game. The heat of her body outdid the cold of his own half and they simply melted in it finally imploding together in each other's climax.

Castle lay peacefully by her side, gently caressing her back.

He stilled and looked at her, a wicked grin building up on his face.

"I don't like the look of that." she confessed shrinking in his arms.

"Well, Kitty... I was thinking... - he paused eyes wide open with excitement – how about a little revenge?" pulling up to pin her to the bed with his own weight.

She gave him a terrified look and he stilled but then she couldn't hold back the roar of laughter that was building up in her throat and she burst out quickly overcoming him until he was now pinned beneath her body.

"Oh Castle... whatever!"

**A/N: What do you think? was it too cruel or just kinky? Anyway... congrats to who guessed right about the ice cube. Till next one...**


	4. Chapter 4

**This is a sequel to Undercover though I'm using the letter H to go on with the alphabet and hopefully finish it. So, if haven't read the first three chapters of Undercover, please do before reading this one. Still having fun with this amazing couple. Enjoy.**

**A/N: I do not own any of these characters.**

**Hickey**

Even if she was straddling him Castle managed to get hold of Beckett's hands and pinned them together behind her back.

"Now... wild kitty... I'm going to make you meow..."

He raised himself up and placed his mouth on her left nipple sucking and biting chuckling every now and then as he realized he had attacked the most sensitive of the two. Powerless as she was, or pretended to be, under his control, she let out short and sharp little cries of pleasure. When Castle moved to the other nipple she arched her back and straddled him even tighter crashing on his groin.

"Ouch! That really hurt! He complained his cheeks turning to a very definite shade of red.

"All is fair in love and... WAR. So... war it is!"

She was still giggling when he rapidly turned over blocking her throbbing body with his strong arms and legs. Beckett thought she could have easily overpowered him once again, her close quarter combat techniques being highly proficient, but she was having such fun and frankly, after what she had just done she reckoned it was only fair to let him have his way with her. A little more teasing perhaps... she mused.

"I bet you don't have the courage to carry on what you're planning to do to me _Kitten..._" she said knowing she had just ignited a nuclear bomb.

"Ahhhh, Beckett... he said starting to bite her on the neck just below the ear lobe – I had told you! _Never ever_... remember?

How could she forget? That moment had been so arousing she still felt the gentle brushing of his whiskers on her cheek as he had leaned on to whisper that famous sentence in her ear. And she had bitten hard her lower lip in anticipation of what those lips could say or do to her. And now she knew. _Wonders..._

The spots he chose to have his little revenge were indeed her most sensitive and she was in awe of his ability not only to find them out but also to memorize them and make an extraordinary use of them to take her to a height she had never reached before. He was marking her on the lower belly when he felt her shudder in his arms and he stopped to look at her with querying eyes.

"Kate?"

"I'm close... please Castle." she begged her pupils wide as she was about to climax.

He slid his hands under her hips and gently lifted her towards his to have better access into her trembling womb. He was overwhelmed by the sensation of her pulsing around him as he had never experienced that before.

"Kate..." he repeated in a lower tone.

"Just... don't stop..." she said then she was unable to utter any more words and they clung together as if their lives depended on it, while a storm of sensations swept their minds away.

Castle was sprawled on the bed savoring blissfully the last part of his well deserved rest after a night of close quarters with his tough and totally hot partner. He was actually dreaming when a loud shrill brought him suddenly back to reality.

"CASTLE!" at that his heart performed its best double somersault ever in his chest and he jumped out of bed panicking.

"Beckett?" he inquired still gasping.

"You... little scoundrel... how do you think I'm supposed to show up to work like this?" she said pointing at the _oh so very visible_ red marks all over her neck.

He recovered from the shock and held her gaze pulling his most effective poker face.

Oh didn't she love him? she thought looking at him in amazement.

"I'm so sorry... Beckett... I really am... _not_!" he said with a mischievous smile.

She couldn't hold her laughter any longer and threw herself at him.

"You don't look so bad yourself Castle... I guess I did quite an interesting job on your route map last night..."

They chuckled amused at each other's irony then he drew her towards him wrapping his legs around her hips and kissing her passionately.

"We're gonna be late..."

"Who cares?" he said matter of fact.

"I do Castle, I am not a best selling author, you know I actually go to work for a living... plus, I don't want Ryan and Esposito rushing here to find out what happened to me. And I have to see Lanie at 10."

"Well, Detective... by the look of it... I'm positive _they_ won't have much guessing to do today..." and he resumed kissing her.

**A/N: Any suggestions for the last chapter? Thanks to all the readers who added my story to their alerts and/or favorites. you do make me so happy.**


	5. Chapter 5

**So here is the final part of Undercover. Thanks everybody for reading this story and for adding it to your favs and/or alerts. I didn't get many reviews but then I'm kind of getting used to that. The amazing figures in my stories stats are such I reward. Writing this has been great fun, I just wanted to start the new year with a smile and these characters are so playful. You all know what I'm talking about. Enjoy and review if you feel like it.**

**A/N: of course I do not own any of these characters. **

**UNDERCOVER **

Part 5

"Good morning Richard." said Martha seeing her son step into the kitchen.

"'Morning Mother."

"Uh uh do we look a bit worn out today?

"I had a … almost sleepless night, that's all."

"Mmm, by what I see, my darling, you most certainly did. And I suppose you enjoyed yourselves?" Martha hinted mischievously staring at his well defined love bites.

"We did." a large smile starting to enlighten his face.

"Richard dear... you're not even trying to deny it? Have I taught you nothing so far?" She teased.

"Mother... you have taught me plenty but... you know exactly whom I was with over the weekend so there's obviously nothing to hide."

"You have a point there, kiddo. So?"

"So what?"

"Does she _really_ make you happy?"

"She does much more than make me happy, you already know that."

She does and she sure knows how to make you forget about the where and when my dear, you're in such a delightful mess. I'm so happy for the two of you."

"Thanks Mother. I made sure to leave her in quite a delightful mess too." They smiled at each other and Castle placed a gentle kiss on her cheek.

"Now Richard, you better have a _huge_ breakfast. Guess you gonna need a hell of a lot of calories in the near future..."

"Mother!"

**C&B**

"Hey Lanie!" said Beckett.

"Hey Beckett" replied the M.E. raising her head from the corpse lying on the table.

"Esposito told me you had some interesting news for me..."

"Well, not as interesting as _those_ you have for me sweetie."

"Excuse me?"

"Oh girl, don't gimme that I-don't-know-what-the-hell-you-talking-about or I'mma smack you!"

She had just stepped into the lab and Lanie had already performed a thorough check-up on her, that was for sure, thought Beckett sensing the temperature rise on her cheeks.

"So...?" Lanie resumed unwilling to let her run away.

"So...?" Beckett copycatted pulling her friend's leg.

"How _is_ he?"

"Well..." - Beckett paused to make a mental picture of what she was about to say – "his eyes you know, Lanie, how gorgeous those blue eyes are..."

"Yeah..." sighed the M.E.

"... and his lips... so sweet and powerful at the same time..."

"Guess I can figure that out..." added Dr. Parish starting to wonder if they had turned down the air conditioning 'cos she was feeling kind of steamy right now.

"... and his hands... I didn't imagine his hands could be so strong yet so gentle... a true maestro."

"...and of course his..." she hinted staring at her friend whose color had risen sensibly at her recounting.

"Now stop right there Detective Beckett or I might need to rush and have a chilly shower at 10 in the morning or a certain you-just-have-to-call-me detective we both know to come and _rescue_ me."

They both laughed out loud.

"Now honey, you can remove that silly scarf you been wearing this morning and show me those delicious war wounds you have all over your neck!" commanded Lanie.

At that Beckett undid the knot of her scarf and Lanie gasped.

"Oh... my … GOD!" she exclaimed. "I am soooo jealous! And he...?"

"He has quite a few nice ones too."

"I'd die to see him get into the precinct and face Ryan and Esposito this morning." said Lanie starting to laugh again.

"Hell, yes!" replied Beckett.

"Now, Beckett. I have never seen you so happy before. Guess getting massive amounts of a famous _very healthy vitamin_ is doing you wonders so I prescribe you carry on taking regular amounts of such vitamin from now on." And the two of them just cracked up.

**C&B**

"Hey Castle!" greeted Ryan and Esposito seeing him approach their desks.

"Guys... how you doing?"

"How _you_ doing bro?" inquired Esposito his eyes locked on a gigantic red mark on Castle's neck. "That mark over there a hickey?" asked Ryan his lips already curling up.

"Yeah." answered Castle proudly.

"Hey partner? Esposito exclaimed looking at Ryan "he's not even trying to deny that! Shall we _interrogate_ the suspect?"

Ryan got immediately into the play and pulled up a serious face "Oh yeah pal, we gonna get as many _details_ as we need this time... stated the cop recalling the night Castle had spent at Beckett's when that bloody psycho was after her - Now Mr Castle, where were you last night, say between eight and seven this morning...?"

"At my partner's." Castle replied matter of fact.

"You were? Added Esposito stepping close to the writer. "and you took good care of her right?"

"I most certainly did. I left her safe and sound this morning at about eight."

"And you made her a nice little breakfast _afterward_...?"

"I did. Coffee and... pancakes. But that was Saturday morning..."

"Jeez Castle! Yelled Esposito – you have spent the whole weekend with our partner?"

"I confess I did." he said muffling his incoming laughter as he perceived the astonishment on their faces.

"Oh dude, you're in so much trouble, you know?"

"And how's that?" asked Castle.

"Because... you're not going to be _released_ until you make a detailed sworn statement of your _brave deeds _with our colleague!"

Castle tried to be as serious as he could be before speaking again.

"Very well detectives but I must warn you before I start that the above mentioned colleague will not be too amused to know about me recounting certain _very private_ deeds. Guess you might want to shoot me first because I don't know what she might do to me guys. Or to you afterward for digging too much into her _very wild_ weekend..." he added knowing he would made them desperate to just grab some bits and pieces of Castle and Beckett's close encounters of the x-rated kind.

"Wild? Jeez bro."

"Such a kick-ass, she sure is pal."

"Now, Mr. New York Times, Pulitzer, whatever best selling author you are... we do hope you have fulfilled all, I quote _all_, her wild dreams because..." Esposito lingered turning to his partner.

"... if you have not"– continued Ryan so very intrigued but the little sketch the three of them were performing – "we will make sure you are going to pay for it!"

"I most definitely did my best over the weekend" - Castle went on blinking at the duo - "but I solemnly intend to carry on my undercover mission in order to make sure my partner is thoroughly satisfied with my line of _investigation_."

At his words and the absolutely totally satisfied ruggedly handsome face he pulled at his friends the trio burst out in a roaring laughter which had everybody turn round in the precinct.

"Castle, you have made me a richer man today." said Esposito suddenly realizing he had just won _the will they/won't they lottery_ of the 12th precinct.

"Damn, bro. I pulled out just last week." - Declared a rather pissed off Ryan. - "You two were simply driving me nuts with that ridiculous dance of yours."

"Come on guys" – said a very proud Castle tapping on his friends' shoulders – "let's go to the Old Haunt and celebrate."


	6. Chapter 6

**Castle readers around the world, I know it's been a while. I woke up with Castle in mind this morning and I decided to write this chapter down. I hope you'll enjoy it just as much as I did writing it. I would like to thank everyone for the nice reviews, the alerts and for adding my FF to your favourites. I'm touched. Lilly**

**A/N: I do not own Castle, but these two characters are such fun to write about.**

**Chapter 6**

Beckett closed her eyes and moaned blissfully. Never ever had her senses been stimulated in such a way and there was only one person responsible for _that_. **Richard Castle**.

Of the power of his imagination she had never doubted since he had been her favorite writer for a long time, she had read all of his novels, and his thinking _outside the box_ had helped her solve more than one case in the past few years. As a _partner _he had proved to be well… from _a nine-year-old on a sugar rush_ to the one who had her back in the most difficult situations, the partner who had saved her life so many times she had almost lost count, the one who had held her hand when that bloody dirty bomb was about to go off leaving both of them suspended in time, staring desperately at each other, trying to express all the regrets for something they would never have… except they had. And as a_ lover_, oh well… Richard Castle had **nothing** more to prove. He was everything a woman could wish for, everything she had always dreamed of. He was her standard in every possible way. He could set her on fire just with those illegal eyes of his. She had seen them shine with laughter, sparkle with tears, strip her bare with desire. His hands were so big yet so gentle she had always been impressed at how delicate they could be. The hands that had brought her coffee for so many years, that had held hers in the most tiring times, brushed her knuckles so gently until…

As the soft yet confident fingers moved along her legs, stroking expertly every single inch of her skin, making her wish them to move upwards and relieve her, Beckett clenched her fists and sighed. Whatever he had planned to do, she would never survive this weekend.

_Earlier that day…_

She couldn't believe he had remained there, sitting on the chair that had become _his_ over the years, watching her do paperwork. He had that look in his eyes she knew damn well, how could she possibly concentrate on the final report when she knew he was looking at her like that? And who was she? A teenager on her first date who cannot control the goose bumps on her skin? It was actually much worse than that, his ability to turn her on just by staring at her, digging his deep blue eyes on her was something that fascinated her. None of her previous partners had ever done that. He was a true maestro at foreplay and right now Detective Beckett sensed he was up to something.

"Castle, what are you doing?"

"Observing you?"

"Really? Doing paperwork? You know better than that."

"Spending quality time with my favorite NYPD detective? You know how much I love watching you doing this." he stated truthfully.

"Do I know?" she teased knowing she loved "being observed" by him just as much. She needed him by her side and she couldn't bear the sight of that empty chair next to her desk any more.

"You're done?" he asked.

"Yeah, this case has driven me nuts. I just wish to go home, fill the tub and forget everything about this."

"You deserve better than that, Kate." He said lowering his voice to a husky promising tone.

Beckett held his gaze and what she found in his widening pupils sent a thrill down her spine. Sure he had different plans in mind, she thought.

He reached out, took the pen out of her hand making sure not to brush her fingers and slowly lowered it on the paper in front of her. "I'm going to kidnap you for the next two days, Detective Beckett. No one has to know about this. And… Kate…" he whispered leaning over till she could feel his hot breath on her ear, "you won't need anything but what you already have on…" he declared giving her his best ruggedly handsome look.

_Game on_. Castle said to himself seeing an astonished and speechless Beckett stare at him in wonder.

"Where are we going?" asked a very intrigued Beckett getting into the cab.

"No, Detective. My plan, my way. Close your eyes, no cheating allowed or I'll have to blindfold you."

_Damn_ she thought closing her eyes. Her heart had skipped a beat just at hearing him say those few words, and the look on the driver's amused face… oh man. "Can I speak, at least?" she inquired sensing he had deliberately chosen to sit on the far end of the rear seat.

"Nope." Was all he said showing the driver a note with the location of the place he was supposed to take them.

"Very well, sir." The man acknowledged with a smile of complicity. Castle nodded and looked at his partner amused. He could see how tense she was. Oh, she was going to make him pay for his boldness but, hell, wasn't he enjoying every single minute of this? And wouldn't she love what was about to come?

"Relax, Kate. We won't be long, I promise." He whispered in her ear. "Right now I suggest you concentrate on _Hearing…_"

_Right! "Apples" won't be enough, most definitely __**not. **_She thought leaning back against the cab seat. Already conjecturing all sorts of very kinky yet painful tricks she could play on him once this _little adventure _was over.

She knew where they were the moment the cab stopped and the door was pulled open. The sound of those engines was unmistakable. The airport.

"Open your eyes Kate, I am not going to carry you on board in my arms." He stated giving her a wicked smile.

"Funny Castle." She replied recalling how he had lifted her like a feather to bring her up to his bedroom just a few nights before.

She opened her eyes and gulped seeing the amazing private jet waiting for them.

"Good morning Mr. Castle. Miss…" Welcomed the pilot, a young, tanned, well-built, dark haired specimen of the male universe.

"Kate Beckett." She said shaking the hand the pilot had offered her.

"Everything's ready. Take off in ten Mr. Castle. Enjoy your flight Miss Beckett."

"Thank you." She replied stepping onto the boarding stairs.

"Champagne?" invited Castle reaching out for the bottle of Dom Pérignon Rosé, 1995. "This is all about… _Taste._" he mused teasingly.

Though not a connoisseur of fine wines, Kate Beckett knew that particular year to be one of the best and rare limited editions in the market of the famous French champagne. Whatever her favorite _writer boy _had decided to celebrate he had chosen the right wine to start with. And strawberries on top of that! Willing to let him have his way with her she relaxed and, picking up one of the deliciously aphrodisiac fruits from the sterling silver bowl in front of her, she brought the tip of the fruit to her lips, lingering there, never diverting her gaze from his. She bit half of the red juicy strawberry then offered him the remaining half. As he parted his lips to receive the fruit she couldn't but notice how large his pupils had become just at her simple gesture. _**Eye for an eye…**_ _Castle, I'm all in!_ she tried to convey with her eyes focused on his mouth making sure not to brush his skin, even if her fingers were dying to run all over his body. This whole scenery of seduction he was creating was painfully arousing and she was determined to drag him into the hottest ever-burning Hell with her.

Beckett opened her eyes. Those magic fingers were slowly but decidedly moving upwards along the inside of her shivering thighs. She writhed in agony on the bed. She could not take any more of this sweet torture. Her mind was already flying high, her body enveloped by the sensual scent of the perfumed oils which had been generously massaged all over her skin. She turned her head, her face lit with pleasure, toward the twin bed next to her, to the blissful face of her partner looking at her. "Castle, please." She begged reaching out for him.

**A/N: the next part should follow soon. Thanks for reading. A review is always appreciated. Lilly**


	7. Chapter 7

**I want to thank everyone for the amazing response to chapter 6 and to this story. Writing Undercover has been great fun, and the reward well, is far beyond my expectations. Enjoy the reading. Lilly**

**A/N: I do not own Castle.**

**Chapter 7**

Castle turned his head to look at the masseuse behind him, then to the masseur who had been taking care of Beckett on the bed next to his.

"Will you excuse us?" he said, his voice low and husky.

The young man behind Beckett lifted unwillingly his oiled hands from the stunning body he had treated for almost half an hour. Of course, knowing who this amazing creature was made it all the more difficult.

"_Carlos, we have a spe__cial guest over the weekend_." the manager had told him a few days before. "_I want you and Liz to outdo yourselves. The last thing I wish is to have one of the best-selling authors of our country rather disappointed because of our service._"

The young masseur recalled how the name _Nikki Heat _had quickly been on every employee's lips and no matter how used he was at seeing beautiful women, **this** particular one had made him swallow hard. The way her eyes had kept his gaze while entering the luxurious couple massage room had sent a shiver down his spine. Not only was she one of the toughest detectives in New York, a real kick-ass in the field, but she also was of the sexiest women he'd ever laid his eyes on. And now he had had the privilege of having his expert hands all over the perfection of her curves.

"Sure Mr. Castle." Said Carlos nodding at his colleague. And the pair promptly left.

Castle got up from his bed careless of the white towel pooling at his feet. The sight of his partner being massaged by another man and begging him almost desperately to come and release her from the sweetest of tortures, while another woman's hands had been running all over his throbbing body had aroused him in a way he had never experienced before. He laid his burning fingers on Beckett's ankles then began to caress her oily skin slowly moving upwards, his hands tracing a dry trail along their route. Reaching the part covered by the towel he deftly found the way beneath the soft, white fabric, making her hold her breath in anticipation. Castle lingered on the smooth ivory skin of her inner thighs, deliberately avoiding to touch her where she wanted, teasing her.

"Castle, do not forget I can shoot you anytime." Beckett threatened, her eyes half-lidded and languid.

"Oh, do I know Detective?" he said placing a series of light kisses on her lower back " yet…" he paused and his hands stilled, leaving her mourning the loss of his touch.

"Oh God Castle, I swear you are **so **going to pay…"

He smiled. "Turn around Kate."

She complied unable to resist him, never breaking eye contact, her cheeks flushed with excitement. Castle took one of the bottles on the table by her bed, poured some scented oil on the palm of his left hand, rubbed it with his other palm then placed his hands on her belly. Her lips parted and a low sexy moan escaped her mouth as he drew circles on her over sensitive skin. He felt her shiver under his touch, struggling to keep herself under control.

"Rick…" she implored arching her back.

He softly brushed her nipples and felt them come to life for him. He bent and kissed her. A long, deep, passionate kiss.

"Kate…" he whispered pulling away, gasping for air. He lifted her from the bed and took her outside, on the amazing terrace on the roof top, by the pool reflecting the warm colors of the sunset.

"Castle, what if somebody…" she exclaimed.

"Don't worry, nobody is going to come here tonight. This beautiful place is just _ours_." Then he lowered her on the immaculate white linen. He kneeled beside her unable to stop looking at her, devouring her with his eyes. "You are … perfect."

She reached out, inviting him in her embrace, the desire of him so intense she feared she might explode. Never ever had any of her previous lovers done anything like this to her. He had taken all of her senses to a height they had never reached, he seemed to know by heart all her secret desires and had made her body sparkle with life.

"Please…" he heard coming back to reality. At that he closed the little space between them.

Kate Beckett looked at the silvery moon and sighed, sated. Castle's head rested peacefully on her breasts while her arms wrapped his strong shoulders. "I want to sleep here, under this incredible sky." She said mesmerized by the calming combination of blues and violets embracing the fading reds and oranges high above. All around lay the quiet Sonoran Desert where he had taken her.

In the silence of the night she let her mind wander free as she gently stroke his nape. _Rick Castle_. How could he be everything she had ever wished for? She loved every single facet of his personality. The reliable partner, the passionate lover, the incredibly talented writer, the sweetest father. But what she really adored about him though was the way he made her laugh. He was so playful…

Suddenly, as if he'd been able to read her inner thoughts, he grabbed the comforter and pulled it over their bodies, sliding underneath. She stiffened.

"Castle, what are you doing?" she let out as he started tickling all her most sensitive places.

"Having a little fun?" It was such a pleasure to hear her giggle like that!

"Ok, Ricky boy. How about a little revenge?" she teased as she quickly overpowered him, pinning him down on the mattress. "I'll make you beg for mercy!" she said, her eyes shining dangerously.

"Game on, _wild kitten_." He whispered giving her a wicked grin. She had that feral look in her eyes he totally loved.

"Now, _naughty writer boy_, just keep still and be ready to get whatever punishment you deserve!"

_Oh damn! _Thought Castle thinking about a very painful kind of punishment he had experienced just a couple of weeks before. However, willing to play her game once more he placed his hands obediently along his sides and lay still.

Beckett lowered her lips on his neck and attacked the most sensitive spots she had learned since their very first night together. Slowly, teasingly, careful not to leave any red marks she ran her lips all over his pulsing neck. Castle closed his eyes and groaned. _And this_, he said to himself, _is just the beg__inning…_

She traveled southward, along the planes of his heaving chest, drawing wet trails with her burning lips. She brushed one of his nipples and saw Castle hold his breath in anticipation. However she deliberately forgot all about the other one, the most sensitive of the two, to move her mouth on his right side, kissing and biting and licking his shivering skin.

"Kate…" he moaned, his voice almost a whisper. She approached his navel, lingering all around but never kissing him the way she knew he loved her to, and when her breasts softly touched his throbbing arousal he let out a strangled groan and stiffened.

Castle thought he was going to black out soon, the desire of her was killing him, his heart beat had never been so wild, he might have a stroke there and then and he would die a happy man. "Kate… please…" he heard himself pleading.

"Did you just beg?" teased Beckett raising her head. _If eyes could talk_ … she thought seeing how the black of his pupils had overcome, almost completely, the incredible blue of his irises. "the best is yet to come…" she said leaning on him to whisper the sweet threat in his ear.

"I am willing to pass out in your arms, Katherine Beckett." He challenged giving her one of his famous mischievous looks.

"Very well then." She said. Never diverting her gaze she lowered her hips on his and started moving so very slowly, teasing him, almost taking him into her. Yet she dragged this crazy game on and on, nearly making him fall over the edge then pulling away.

"Jesus Kate. I can't…"

"What Rick? You can't what?

"Please… " he begged once more.

"Good." She said with a grin, "Who is in charge here?"

"You are."

At that she slid down his length, her burning half meeting his aching one. So slowly he wanted to scream. Then she stopped. Looked at him and withdrew. He gasped feeling her leave.

" Kate, I swear I'm going to die." He confessed unable to take any more of the torture she had chosen to inflict on his throbbing self. He had always known that Kate Beckett was tough, she had been so hard to conquer, but her inner self, the side of her that was so playful, that was capable of driving him insane, was something that had been so unexpected, even for his wild, vivid imagination.

Beckett stilled, her playfulness disappeared together with the feral look and she tried to convey with her eyes what she really felt for him. She lowered her lips on his, almost touching them. "I love you." she vowed as she welcomed him into her once again. She started moving her hips to a rhythm unknown to both of them, so slow and gentle, her mouth matching the same pace of their lovemaking. He pulled her close to his body, knowing they were so close, the friction of their wet skin impossible to bear.

They simply shattered and their moans filled the most incredibly starry night each of them had ever witnessed, in the middle of the desert, surrounded by the smooth silhouettes of the mountains in the far distance, their bodies shining under the silvery touch of the enchanting moon.

**A/N: I will go on a hiatus for a while. I'm trying to finish some stories in Italian and right now I find it really difficult to write in both languages. I'll be back soon. Lilly**


	8. Chapter 8

**I've decided to post a new chapter of Undercover, a follow-up to chapter 7, set at the SPA in the middle of the Sonoran Desert. An homage to one of my favourite writers. **

**I'd like to thank everyone for the amazing response to this story. Enjoy the reading, Lilly.**

**I do not own Castle.**

**UNDERCOVER**

**Chapter 8**

The harsh scream of a mountain lion woke her up in the middle of the night. Kate Beckett opened her eyes and looked up at the sky under which they had fallen asleep. The moon, half-hidden behind the clouds, cast an eerie glow on the terrace and the peaceful Sonoran desert all around. Most of the stars had disappeared and the air smelled like rain. A storm was approaching.

She looked at Castle sleeping calmly beside her, his right leg and right arm wrapped on her body, possessively, in a way she had simply come to adore. She smiled at the thought that she had never allowed any of her previous lovers to really possess her. But Castle was different. He had always been. And although she would never openly admit it to him, she loved the way he circled her body, instinctively protecting her even in his sleep.

She pulled away smoothly from his embrace and got up, her body deliciously sore and her skin still ablaze with their love-making. She walked to the brink of the pool and glanced at the reflection of the pale moon flickering on the water.

_That would do_, she thought, _a nice swim, to release some of the energy still flowing through her._ She slipped into the water and plunged towards the bottom, swimming all the way through the other end of the pool.

Suddenly she felt two strong hands grab her hips and flip her around. Taken by surprise, she fought the urge to open her mouth and breathe, her heart beat racing in her chest as Castle pressed his lips on hers, pulled her close to his body and breathed air into her mouth. Then, holding her firmly against him, he pulled her up to the surface. Beckett gasped and looked at him bewildered.

"Castle, are you crazy? Why on earth did you do that?" she yelled.

"I just couldn't refrain myself, Kate, you were so beautiful, … naked, …under the moonlight…"

The wild, almost feral, look in his now dark blue eyes sent a shiver down her spine. She felt like a prey in his arms, it was a feeling totally new and thrilling at the same time. Her body responded on its own volition, she slipped away from his grip, reached the ladder and turned around,

"Try and catch me." She challenged him with a wicked grin. She climbed out and started to run.

For a moment Castle just stood there and looked at her, Aphrodite emerging from the water, her body fully exposed to the silvery glow of the moon. Then he let out a low, husky groan and dashed out of the pool.

There was a flash in the sky and everything was suddenly lit up before the sound of thunder enveloped them. They both stilled and stared at each other, rivulets trickling down their skin, chest heaving and eyes sparkling with desire. Large drops began to fall down, heavy and cold, on their burning skin. She screamed at the unexpected feeling, turned around and smiled at him, amused. Then she resumed her run, offering her body to the pouring rain.

Castle grabbed a large towel from one of the _chaises-longues_ nearby and ran after her. He had always thought she would be special, but never ever, not even in his wildest dreams had he thought that his partner, the kick-ass detective who could kill him with just one look, would match all of his fantasies.

And this was the right night for one of them.

Looking at her running wild under the rain he couldn't but think that she probably had never done that before either and his body shivered in anticipation as he pursued his exciting chase.

"Got you!" he said wrapping his strong arms around her. She screamed and tried to escape but Castle's hold felt too good this time and she went pliant in his arms. "**Mine," **he whispered in her ear, pressing his arousal on her body. He circled her with the towel then lowered her gently on the tiled floor, by the brink of the pool. "I'm going to take you _short and sharp_." He said sliding into her, his chest pressed on her back, his arms protecting her from the hard surface underneath.

"God, Castle!" she was able to say before her brain lost contact with reality. _How could __his strong body be so light on hers? And how could such a brief moment with him inside her be so intense?_ She had no answer, all she could do was let herself go and be swept away by the strongest wave of pleasure she had ever felt. With one final thrust Castle buried himself deep inside her. "Kat…" her name died in her ear and the last thing she sensed was the desperate throbbing of their bodies under the cold rain that was pouring down on them.

"We should get up, Castle, you don't want to drown in here, do you?" she teased unwilling to move.

"Definitely not." He chuckled and the friction of his sex inside her sent an unexpected wave of hot sparks shooting in her womb.

"Don't stop." She heard herself beg.

"What?" he asked puzzled.

"Chuckling, Castle, that felt … incredible!" she confessed.

"Like _**this**_?" he said giggling again.

"Yes," she whispered, "yes, exactly like _**that**_."

"Oh, Beckett, you are the most sensual, arousing, damn sexy creature I have ever seen." he paused and inhaled deeply; feeling very much alive inside her again he resumed his thrusts, slowly, softly, to prolong her ecstasy as long as he could, until he was unable to resist any longer and his mind blacked out.

**C&B**

"Still cold?" he inquired.

"Not anymore, this is actually very nice Castle." She said nodding at the fire beside them. The way he was rubbing her wet hair dry sent a trail of goose bumps down her spine. Though he was standing behind her he noticed how her nipples had stiffened. "Definitely very nice." He stated slowing his movements down, taking his time, massaging her head with his fingers.

"Castle," She moaned pulling her head backwards till it was resting on his shoulder.

Her naked body reflected the dancing flames of the fireplace. She felt her skin alight again and she was unable to tell if it was because of the fire, or Castle, or both. She closed her eyes and focused on the delicious feeling of his fingers running on her scalp.

"Rick…" she said almost in a whisper, completely abandoned to his touch, shivering with pleasure as he massaged that powerful part of her body. Castle knew, oh he had learned that so well, that if he kept digging his fingertips on the back of her neck like that he would bring her to a new climax.

But all of a sudden he stopped.

"Castle!," she protested, eyes closed, her mind still whirling, "oh God, why did you just…?"

"Ssh, lie down and keep your eyes closed." He susurrated in her ear, in a low and deep tone. She obeyed, willing to play whatever new game he intended to. Then she felt his hot breath on the still wet curls of her mound "Be patient, Lady Jane," he said with a tender kiss before leaving the room.

An image flashed her mind. _Did he really…?_ _No,_ she said to herself, _how could he possibly?_ _Not in the middle of the desert… _then her lips turned upwards. Castle was simply Castle, and nothing could stop his vivid imagination. She heard him come back and move close to her, the sweet scent of the flowers confirming the idea that had formed in her mind.

"I won't even ask how or when you managed to get those flowers, Castle." She said teasingly.

"Oh well, dear _Connie_, never underestimate the ability of your cheeky writer," he said quite satisfied with the job he was doing, "There, these forget-me-nots are just perfect on your brown maiden hair."

"Will you be my _Mellors_ then?" She asked opening her eyes to take a look at the light blue little flowers resting on her curls.

"Why, Katherine Beckett I never thought you would engage in such readings?" he teased realizing she was actually enjoying herself a lot.

"Oh well, Richard Castle, I guess you still haven't unveiled _**all **_of my secrets." She replied as she threaded a couple of bluebells around his sex. "Oh, you are really beautiful, my _naughty_ game-keeper." She kept decorating his body giggling amused at the sight of his manhood coming to life as she softly touched its sensitive skin.

"Now Ricky boy, she continued suddenly straddling him, pinning his wrists over his head, easily overpowering him, "how can I make you pay for leaving me empty-handed just now, uhh?, she paused, giving him a mischievous look."

"Can I use my safe word?" he chuckled knowing he would drive her crazy.

"Oh, Castle a basket full of apples would **not** be enough this time." At that she began to tickle him in his most sensitive areas, laughing out loud at the way he twisted and squirmed under her deft fingers. "And once I'm done with your punishment," she threatened lowering on his ear, her voice a sensual whisper, "I'm going to have my way with you, _short and sharp…"_

"Oh Kate, you are something!"

**A/N: I'll be back in the fall, have a nice summer holiday, thanks for reading, Lilly**


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